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- Andersson, Niklas, 1970, et al.
(author)
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Investigation of central versus peripheral effects of estradiol in ovariectomized mice
- 2005
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In: J Endocrinol. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 187:2, s. 303-9
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Journal article (peer-reviewed)abstract
- It is generally believed that estrogens exert their bone sparing effects directly on the cells within the bone compartment. The aim of the present study was to investigate if central mechanisms might be involved in the bone sparing effect of estrogens. The dose-response of central (i.c.v) 17beta-estradiol (E2) administration was compared with that of peripheral (s.c.) administration in ovariectomized (ovx) mice. The dose-response curves for central and peripheral E2 administration did not differ for any of the studied estrogen-responsive tissues, indicating that these effects were mainly peripheral. In addition, ovx mice were treated with E2 and/or the peripheral estrogen receptor antagonist ICI 182,780. ICI 182,780 attenuated most of the estrogenic response regarding uterus weight, retroperitoneal fat weight, cortical BMC and trabecular bone mineral content (P<0.05). These findings support the notion that the primary target tissue that mediates the effect of E2 on bone is peripheral and not central.
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| 2. |
- Löf, Marie, 1971-, et al.
(author)
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Changes in basal metabolic rate during pregnancy in relation to changes in body weight and composition, cardiac output, insulin-like growth factor I, and thyroid hormones and in relation to fetal growth
- 2005
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In: American Journal of Clinical Nutrition. - 0002-9165 .- 1938-3207. ; 81:3, s. 678-685
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Journal article (peer-reviewed)abstract
- Background: The total energy cost of pregnancy is largely due to an elevated basal metabolic rate (BMR). Large variations in the BMR response to pregnancy have been reported, but the factors associated with this variability are incompletely known.Objective: The objective was to identify factors associated with variability in the BMR response to pregnancy.Design: In 22 healthy women, BMR, body weight (BW), total body fat (TBF), fat-free mass (FFM), circulatory variables, serum concentrations of insulin-like growth factor I (IGF-I), and thyroid hormones were measured before pregnancy and in gestational weeks 14 and 32. BMR and BW were also measured in gestational weeks 8, 20, and 35. Fetal weight was estimated in gestational week 31.Results: In gestational week 14, the increase in BMR correlated significantly with the corresponding increase in BW and with the prepregnancy percentage of TBF. Together these variables explained ≈40% of the variability in the BMR response. In gestational week 32, the increase in BMR correlated significantly with the corresponding changes in BW, TBF, FFM, IGF-I, cardiac output, and free triiodothyronine. The increase in BW in combination with fetal weight or with the elevated concentration of IGF-I in serum explained ≈60% of the variability in the increase in BMR.Conclusions: Weight gain and the prepregnancy percentage of TBF—ie, factors related to the maternal nutritional situation—are important factors with regard to the variability in the BMR response to pregnancy. Thus, it is important to consider the nutritional situation before and during gestation when assessing pregnancy energy requirements.
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